/**
 * Created by dell on 2017/7/21.
 */
public class ScannerKeyboardTest {
    public static void main(String[] args) {
//        Scanner sc=new Scanner(System.in);
//        //System.out.println(" "+sc.hasNext());
//        //sc.useDelimiter("\n");
//        while(sc.hasNextLong()){
//            System.out.println("输入的内容是："+sc.nextLong());
//        }
//        String st="q w r f cvbnh";
//        System.out.println(st.toCharArray());
        StringBuilder sb=new StringBuilder();
        sb.append("java");
        sb.insert(4,"hello");
        sb.replace(4,4," ,");
        sb.reverse();
        System.out.println(sb);
    }
}
